(M59) Whatever may be thought of these speculations, we know that many solemn rites were celebrated by the ancient Greeks at intervals of eight years.(197) Amongst them, two deserve to be noticed here, because it has been recently suggested, with some appearance of probability, that they were based on an octennial tenure of the kingship.(198) One was the Festival of the Crowning at Delphi; the other was the Festival of the Laurel-bearing at Thebes. In their general features the two festivals seem to have resembled each other very closely. Both represented dramatically the slaying of a great water-dragon by a god or hero; in both, the lad who played the part of the victorious god or hero crowned his brows with a wreath of sacred laurel and had to submit to a penance and purification for the slaughter of the beast. At Delphi the legendary slayer of the dragon was Apollo; at Thebes he was Cadmus.(199) At both places the legendary penance for the slaughter seems to have been servitude for eight years.(200) The evidence for the rites of the Delphic festival is fairly complete, but for the Theban festival it has to be eked out by vase-paintings, which represent Cadmus crowned with laurel preparing to attack the dragon or actually in combat with the monster, while goddesses bend over the champion, holding out wreaths of laurel to him as the mede of victory.(201) It is true that in historical times Apollo appears to have ousted Cadmus from the festival, though not from the myth. But at Thebes the god was plainly a late intruder, for his temple lay outside the walls, whereas the most ancient sanctuaries stood in the oldest part of the city, the low hill which took its name of Cadmea from the genuine Theban hero Cadmus.(202) It is not impossible that at Delphi also, and perhaps at other places where the same drama was acted,(203) Apollo may have displaced an old local hero in the honourable office of dragon-slayer.